A remake of the original Portal mod, Memories! The idea behind this is to make an episodic mod, which you can play as it grows and every new chapter will be based on a whole new theme.
Upon returning to the village you grew up in as a child, you discover that it's empty. Doors are boarded up, bloodstains soak the ground, and a strange aura lingers in the air. What happened and why has everyone disappeared?